Large earthmoving equipment, for example drill rigs, front shovels, and excavators, are often tethered to receive electrical power from a stationary source via large, high-voltage cables connected to the equipment. The electric cables may lie across the ground of a worksite or along a bench floor during operation of the equipment. As the equipment moves to a new location, for example when the equipment travels to a new drilling site or pivots between drilling targets, the cables are dragged across the ground and the position of the cables changes relative to the ground.
Other pieces of non-tethered mobile equipment, some manned and some autonomous or semi-autonomous, are commonly co-located with the tethered machines at the worksite and navigate about the worksite performing other excavation and/or transportation activities. During operation of these other pieces of mobile equipment, contact with the aforementioned electric cables should be avoided so as to prevent damage to the electric cables and the equipment. However, mobility and navigation around the electric cables can be difficult because the cables may be hard to see and their locations do not always remain the same.
One system for supplying continuous electrical current to mobile equipment while protecting the associated power supply cable is described in U.S. Pat. No. 4,587,383 of Stoldt, issued May 6, 1986 (“the '383 patent”). The '383 patent discloses a large front-end loader that is electrically powered by way of a cable connected to a turret that is rotatably mounted on top of the machine. The turret has a height sufficient so that the flexible cable, as it enters the turret, is elevated above the highest fixed portion of the machine. In this manner, with the bucket of the loader in its lowered and working position, the machine has complete freedom of rotation and movement under the elevated cable, and the cable is kept off the mine floor where it might be damaged or create a safety hazard.
Although the system described in the '383 patent may help reduce damage to a cable caused by a machine that is tethered to the cable, the benefit thereof may be limited. That is, the system of the '383 patent may do little to protect the cable at locations away from the immediate vicinity of the tethered machine, where other machines may be operating that could damage the cable. In addition, the extended height of the turret may limit the use of the machine in some applications and/or increase the likelihood of damage to the machine caused by collision of the turret with overhead obstructions.
The tether tracking system and method of the present disclosure is directed toward improvements in the existing technology.